variations of soil and climate. Thus, a Sweet Cherry tree can be told from a tree of the Sour Cherry, or the English Morello can be distinguished from Montmorency by branch characters as far as the outlines of the trees are discernible. Few cherries bear spines but all are more or less spurred and these spurs are quite characteristic even in varieties. With the branchlets the length of the internodes should be considered and their direction, whether straight or zigzag; also color, smoothness, amount of pubescence, size and appearance of the lenticels, the presence of excrescences, are all to be noted in careful study though all are more or less variable, pubescence especially so, this character being too often relied upon in descriptions by European botanists and pomologists.

Leaf-buds vary greatly in different species in size, shape, color of the buds and of their outer and inner scales and in the outline of the scales. The angle at which the bud stands out from the branchlet is of some taxonomic value. Vernation, or the disposition of the leaf-blade in the bud, is a fine mark of distinction in separating the cherry from other stone-fruits and while all cherry leaves are supposed to be conduplicate, that is, folded by the midrib so that the two halves are face to face, yet there are slight but important differences in the conduplication of the leaves in both species and varieties. The manner of bearing buds—whether single, in pairs, or in rosettes—must be taken into account, with species at least, and differences in shape and position of leaf and fruit-buds must be noted.

Leaves in their season are very evident and either collectively or individually are valuable determinants of species and varieties. Fruit-growers take little note of leaves, however, though they should be taken into practical account, since their size and number often indicate the degree of vigor. The variability of leaves is usually within limits easily set and occurs most often in young plants, in extremes of soil and climate, and on very succulent growths or water-sprouts. Leaf-size is the most variable character of this organ but is yet dependable in separating several species, as, for example, Prunus avium from Prunus cerasus, the leaves being very much larger in the former than in the latter species. Leaf-forms are very constant in species and varieties, hence especially valuable in classification.

Much care has been taken to illustrate accurately the size and form of cherry leaves in the color-plates in this text but it is impossible to reproduce by color-printing the tints of the leaves, though these are quite constant in both species and varieties.

Other characters of leaves taken into account in describing cherries are thickness, roughness, and pubescence, all of which are somewhat variable, being greatly influenced by climate and soil. Quite too much stress is laid upon the value of pubescence on leaves in determining groups, unless comparisons can be made between plants growing in the same habitat. Possibly more important than any other part of the leaf-blade, in the study of species at least, is the margin. This in the cherry is always serrated and often sub-serrated. These serrations are best studied at the middle of the sides of the leaves, those at the base and apex often being crowded or wanting.

The petiole may be used to good advantage in distinguishing both species and varieties. Thus, in consequence of the great length and slenderness of the petiole of leaves of Sweet Cherries, the leaves are always more or less drooping, while those of the Sour Cherry are usually erect by reason of the petiole being short and strong. The color of the petiole is said by some to be correlated with that of the fruit—a statement that needs verification. The pubescence of the petiole must be noted.

The position, size, shape and color of the glands on cherry leaves must be noted as they are fairly constant guides. They are usually on the petiole at the base of the leaf but are sometimes on the leaf itself. The glands are commonly given as globular or reniform in shape but there are often intermediate forms the shape of which is hard to classify.

Stipules in this plant have considerable taxonomic value, having some distinguishing marks not possessed by the leaves. Cherry leaves springing from dormant leaf-buds have very small stipules, sometimes so minute as hardly to be seen, but on the current year's growth the stipules are larger, being largest at the tip of the branchlet. There is considerable difference in the size of these organs in varieties of the same species. Stipules of the cherry are nearly always borne in pairs. The small stipules, appearing with the first leaves, drop, at this Station, about the middle of June while those accompanying the later leaves on the wood growth of the current year remain until in July, there being a difference in varieties as to how long they remain. All stipules are deeply toothed and bear glands of varying color and shape on the serrations, the characters of both serrations and glands offering some distinguishing marks for species and varieties.

The flowers of cherries are very characteristic, as a study of the color-plates of blossoms will show, furnishing a wholly distinctive mark of species and helping to distinguish varieties. The flowers are hermaphrodites and are borne in more or less dense, corymbose clusters. Individual flowers in species and varieties vary in size, shape, color and odor. The peduncles are long or short, as the case may be; the corolla furnishes distinctions in size, shape and color of petals; the calyces are chiefly distinguished by their glands and the amount and character of the pubescence; while stamens and pistils offer differences in size, color of their different parts and in the number of stamens. In plums the reproductive organs differ greatly in ability to perform their functions, some varieties being self-sterile. In New York there seem to be no marked differences in fecundity in cherries nor are there so frequently the malformations of reproductive organs which are found in plums. The season of flowering is a fine mark of distinction between species and varieties, a fact well brought out by the chart on pages 80-81.

Of all organs, the fruit of the cherry is most responsive to changed conditions and hence most variable, yet the fruits furnish very valuable taxonomic characters in both botany and pomology. In pomology, in particular, the fruits must be closely studied. Size, shape, color, bloom, stem, cavity, apex, suture and skin are the outward characters of which note must be made; while the color, aroma, flavor and texture of the flesh are usually very characteristic. Both species and varieties are well distinguished by the time of ripening though there is much variation in ripening dates. The keeping quality is scarcely taken into account with cherries but varies a great deal, chiefly in accordance with firmness of the flesh. The flesh of cherries, as in all drupaceous fruits, clings to the stone or is wholly or partly free—a character of interest both to the systematist and to the fruit-grower. The color of the juice, whether colorless or red, is a plain and certain dividing line in both species and varieties.

The pits of cherries are rather more lacking in distinction than in other stone-fruits, plums for example, yet they must be accounted of considerable value in determination and for this reason have been included in all of the color-plates of varieties. Cherry-pits from individual trees are almost lacking in differences except in size but between species and varieties show many distinctions not only in size but in shape, surfaces, grooves and ridges, in the ends and more or less in the seeds within. Cherries of any variety grown on poor soils or in incongenial climates tend to have large stones and